Which is why you might have been shocked when Shoshanna (Zosia Mamet) dropped the Virginity Bomb at the end of episode two. Encountering a 20-something of that persuasion in New York City is akin to seeing a unicorn prance up Fifth Avenue (with President Obama on its back, shooting rainbows from his hands).

After Shoshanna's wrenching encounter with fellow Camp Ramah alum Matt in episode four (come on, dude -- she's, like, the "least virgin-y virgin ever"), HuffPost TV got to thinking: Is Shoshanna giving a voice to late-in-life virgins -– a portion of the population that, for the most part, hasn’t been depicted?

To answer that question and many more, HuffPost spoke with Amy Rosenberg, sex therapist and associate director of Human Sexuality at NYU Langone Medical School

When Shoshanna tells Matt she wants to lose her virginity to him, he declines her by saying, "It's just like virgins get attached. Or they bleed. You get attached when you bleed." Is that a pretty typical sentiment from men?
I haven't heard it quite like that. But there are certainly other psychological implications of a first time, sometimes. For some women, and for some men.

Is virginity late in life (that's not for moral or religious reasons) a pretty unusual thing in America these days?
Well, it's pretty rare now. If we're talking about 25-to-29 year-olds, seven percent of unmarried women have not had sex. And only five percent of women 30-34. And four-point-three percent ages 35-39. So you gotta figure, in that grouping, there are probably a few that are saving themselves for moral or religious reasons.

So what are the psychological implications of that? For Shoshanna in “Girls,” there's a lot of shame involved -- it's something she keeps secret. Is that the norm for late in life virgins?
I think there are reasons that women -- or men, also -- have not had intercourse. Sometimes they miss an opportunity. It's just easier to do in high school or college when there's the appropriate time of not knowing what you're doing. And if you miss that window and you're 25 or you're 30, people have started to think, "What's wrong with this person?" This man who I saw in a treatment this morning -- he's 25 years old -- said, "My sister wants to fix me up with this girl, she's 28, but I heard she's a virgin." And I said, "So what are your thoughts about that?" And he said, "Well, the negative is we probably won't be having sex. But it's nice to know that she's not a complete slut." Also, for him, he was talking about the bar not being set all that high. So he didn't have any questions about his performance. There's also that idea of territorialism, wondering who's been there before.

Why do you think some women wait, and then box themselves into a corner once they’ve hit their mid-20’s?
Sometimes it's pure shyness –- not knowing how to do it. I don't mean sex, but how to maneuver those social situations. There can be body image questions and issues, fear of it physically hurting. Fear that they're going to get too attached, which is what the character in “Girls” was saying. Then, if they're too attached, there's a fear of being left. And some women who have been hurt. If they've been physically or emotionally hurt, they've been scarred with some of those past experiences. And they're scared.

Is there a difference between a virgin becoming attached after sex and a non-virgin becoming attached after sex? Because, in a woman's biology -– regardless of promiscuity -– she's hard-wired to become attached.
For some women. I can't make the generalization. Some women ask a male friend to help them out. Or they just get drunk and do it. They sometimes -- later in life -- make a plan and say, "Tonight's the night." In a way, just to get it behind them. But I've heard that from younger women also.

That sounds like what I've heard time and time again -- the societal pressure to, "Just get it over with." Where does that come from? Why is virginity such a dirty word now?
It's interesting that you say it that way, because it used to be this badge of honor. And at a certain age, it's not. Because also, what this man was saying to me today, he said, "Well I wonder what's psychologically wrong with her. And I wonder what's wrong with her, physically." It was almost like he wasn't going to go there -- he wasn't going to be the first. Unlike this idea of deflowering a young virgin, it's not the same idea of getting there first with an older woman.

That's what fascinates me so much about what “Girls” brings up: the idea that taking a woman's virginity, for men, can evolve from being a conquest to being a burden. It just depends on how old the virgin is.
A burden, and damaged. And also, these women are feeling damaged. I think it's this idea -- maybe not so much peer pressure that you're talking about, but this idea that they're not feeling normal and they're feeling isolated and frankly they feel like they're missing out on part of life. And they are. And very often it keeps them out of relationships. They fear having to talk about it. It's conflicted -- they want to get involved, but they also fear getting involved because they know it will have to come out. And they're feeling like a freak already because they have not gone through the normal developmental stages in life.

So what advice would you give Shoshanna? Would you tell her to just lie to her next sex partner so she can do the deed? Would you tell her to have sex with a friend? Or to wait until she has a serious boyfriend?
I think I would still normalize it and understand with her why she is waiting, what she's waiting for. And I think I'd explore the psychological blocks to intimacy –- emotional and physical intimacy. I don't tell people what to do, I try to understand why it is they're at this point in their lives and what they want to do about it. And playing out the scenarios with them, letting them come up with ideas of the options.

What do you see most of your late-in-life virgin patients doing to take action and lose their virginity? Do they just lie to their partner?
Sometimes they do, but I'm thinking of this woman in her 30s who was scared of it, and she'd be in a relationship and she'd end it before it got to that point. They knew she was a virgin, and when it got closer to actually doing it she'd end the relationship. And she found a wonderful man, and that's when she really felt comfortable enough with herself to actually go through with it in a way that felt loving. And it's interesting that that's the option we haven't talked about yet. Of actually working through all of one's fears and dating and meeting someone that she was actually falling in love with, and that's where she felt safe enough. It's the idea of safe for many women, too.

In that vein, it's as if virginity is just another issue on the long list of issues that any person brings to a relationship.
It's another thing. And it's kind of a symptom of something else. Of whatever the fears are. Whatever the concerns are about their bodies. Whatever their ideas are. Often there's an issue of abandonment, and they don't want it to happen again. So in therapy…it’s not just, "These are the steps to take just to go do it." I love when it happens in that taking one's time, loving way – even when you're feeling stigmatized by it. And I think these women are feeling stigmatized with their girlfriends, also. They'll have girl’s night out or be at a party or dinner, and the talk turns to sex, and very often she hasn't disclosed to her friends that she's a virgin. So she just withdraws from the conversation.

The way you're describing it, is it safe to assume that late-in-life virgin women have similar behavior patterns to late-in-life virgin men? Especially when it comes to being ashamed and keeping it a secret from friends?
It is kind of the same. But for women, it's a little bit more OK not to know what they're doing sexually. Just a little bit. Where men are supposed to know what they're doing. And there's also a much higher degree of sexual dysfunction among men who have waited longer. It all comes from their minds -– it comes from the anxiety. It's a version of performance anxiety.

As a sex therapist who works with late in life virgins, how do you feel about the fact that their plight is finally being addressed in a talked-about show?
It’s great -– people want to see people like themselves! I have a lot of gay patients who talk about how wonderful it is to see gay relationships on TV. Or black patients who talk about wanting to be able to connect to a storyline. That they're not alone -- it takes away that isolation.